On Fri, Mar 03, 2023 at 05:57:41PM +0800, Baolu Lu wrote: > On 2023/3/3 17:32, Jean-Philippe Brucker wrote: > > > I suppose the common thing is reserving some kind of special PASIDs. > > Are you planning to use RID_PASID != 0 in VT-d? Otherwise we could just > > communicate min_pasid from the IOMMU driver the same way we do max_pasid. > > > > Otherwise I guess re-introduce a lighter ioasid_alloc() that the IOMMU > > driver calls to reserve PASID0/RID_PASID. > > Yes. We probably will use a non-zero RID_PASID in the future. An > interface to reserve (or allocate) a PASID from iommu_global_pasid_ida > should work then. Just allowing the driver to store XA_ZERO_ENTRY would be fine Jason
